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188 lines
4.7 KiB
C
188 lines
4.7 KiB
C
#include "Python.h"
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#include "pycore_dict.h" // _PyDict_DelItemIf()
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#include "pycore_object.h" // _PyObject_GET_WEAKREFS_LISTPTR()
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#include "pycore_weakref.h" // _PyWeakref_IS_DEAD()
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#define GET_WEAKREFS_LISTPTR(o) \
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((PyWeakReference **) _PyObject_GET_WEAKREFS_LISTPTR(o))
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/*[clinic input]
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module _weakref
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[clinic start generated code]*/
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/*[clinic end generated code: output=da39a3ee5e6b4b0d input=ffec73b85846596d]*/
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#include "clinic/_weakref.c.h"
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/*[clinic input]
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@critical_section object
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_weakref.getweakrefcount -> Py_ssize_t
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object: object
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/
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Return the number of weak references to 'object'.
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[clinic start generated code]*/
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static Py_ssize_t
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_weakref_getweakrefcount_impl(PyObject *module, PyObject *object)
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/*[clinic end generated code: output=301806d59558ff3e input=6535a580f1d0ebdc]*/
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{
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if (!_PyType_SUPPORTS_WEAKREFS(Py_TYPE(object))) {
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return 0;
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}
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PyWeakReference **list = GET_WEAKREFS_LISTPTR(object);
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Py_ssize_t count = _PyWeakref_GetWeakrefCount(*list);
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return count;
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}
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static int
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is_dead_weakref(PyObject *value)
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{
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if (!PyWeakref_Check(value)) {
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PyErr_SetString(PyExc_TypeError, "not a weakref");
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return -1;
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}
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return _PyWeakref_IS_DEAD(value);
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}
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/*[clinic input]
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_weakref._remove_dead_weakref -> object
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dct: object(subclass_of='&PyDict_Type')
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key: object
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/
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Atomically remove key from dict if it points to a dead weakref.
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[clinic start generated code]*/
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static PyObject *
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_weakref__remove_dead_weakref_impl(PyObject *module, PyObject *dct,
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PyObject *key)
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/*[clinic end generated code: output=d9ff53061fcb875c input=19fc91f257f96a1d]*/
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{
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if (_PyDict_DelItemIf(dct, key, is_dead_weakref) < 0) {
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if (PyErr_ExceptionMatches(PyExc_KeyError))
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/* This function is meant to allow safe weak-value dicts
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with GC in another thread (see issue #28427), so it's
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ok if the key doesn't exist anymore.
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*/
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PyErr_Clear();
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else
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return NULL;
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}
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Py_RETURN_NONE;
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}
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/*[clinic input]
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@critical_section object
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_weakref.getweakrefs
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object: object
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/
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Return a list of all weak reference objects pointing to 'object'.
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[clinic start generated code]*/
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static PyObject *
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_weakref_getweakrefs_impl(PyObject *module, PyObject *object)
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/*[clinic end generated code: output=5ec268989fb8f035 input=3dea95b8f5b31bbb]*/
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{
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if (!_PyType_SUPPORTS_WEAKREFS(Py_TYPE(object))) {
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return PyList_New(0);
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}
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PyWeakReference **list = GET_WEAKREFS_LISTPTR(object);
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Py_ssize_t count = _PyWeakref_GetWeakrefCount(*list);
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PyObject *result = PyList_New(count);
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if (result == NULL) {
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return NULL;
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}
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PyWeakReference *current = *list;
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for (Py_ssize_t i = 0; i < count; ++i) {
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PyList_SET_ITEM(result, i, Py_NewRef(current));
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current = current->wr_next;
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}
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return result;
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}
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/*[clinic input]
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_weakref.proxy
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object: object
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callback: object(c_default="NULL") = None
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/
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Create a proxy object that weakly references 'object'.
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'callback', if given, is called with a reference to the
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proxy when 'object' is about to be finalized.
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[clinic start generated code]*/
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static PyObject *
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_weakref_proxy_impl(PyObject *module, PyObject *object, PyObject *callback)
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/*[clinic end generated code: output=d68fa4ad9ea40519 input=4808adf22fd137e7]*/
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{
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return PyWeakref_NewProxy(object, callback);
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}
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static PyMethodDef
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weakref_functions[] = {
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_WEAKREF_GETWEAKREFCOUNT_METHODDEF
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_WEAKREF__REMOVE_DEAD_WEAKREF_METHODDEF
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_WEAKREF_GETWEAKREFS_METHODDEF
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_WEAKREF_PROXY_METHODDEF
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{NULL, NULL, 0, NULL}
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};
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static int
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weakref_exec(PyObject *module)
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{
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if (PyModule_AddObjectRef(module, "ref", (PyObject *) &_PyWeakref_RefType) < 0) {
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return -1;
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}
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if (PyModule_AddObjectRef(module, "ReferenceType",
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(PyObject *) &_PyWeakref_RefType) < 0) {
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return -1;
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}
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if (PyModule_AddObjectRef(module, "ProxyType",
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(PyObject *) &_PyWeakref_ProxyType) < 0) {
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return -1;
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}
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if (PyModule_AddObjectRef(module, "CallableProxyType",
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(PyObject *) &_PyWeakref_CallableProxyType) < 0) {
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return -1;
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}
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return 0;
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}
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static struct PyModuleDef_Slot weakref_slots[] = {
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{Py_mod_exec, weakref_exec},
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{Py_mod_multiple_interpreters, Py_MOD_PER_INTERPRETER_GIL_SUPPORTED},
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{0, NULL}
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};
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static struct PyModuleDef weakrefmodule = {
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PyModuleDef_HEAD_INIT,
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"_weakref",
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"Weak-reference support module.",
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0,
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weakref_functions,
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weakref_slots,
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NULL,
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NULL,
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NULL
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};
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PyMODINIT_FUNC
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PyInit__weakref(void)
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{
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return PyModuleDef_Init(&weakrefmodule);
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}
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